The invention thus concerns bottles of liquid, notably containing at least about 10 liters of liquid, often water, typically three, four or five gallon bottles, which are used in the upside-down position in drinking water dispensing fountains. Presently most of the bottles of this type are made in polycarbonate and may therefore be reused many times, while being cleaned before each filling. During the lifetime of such a bottle, the outer face of its neck gets damaged, which requires that an added flexible seal gasket, be provided in the bottom of the closure for closing the neck of the bottle, which avoids leaks by accommodating scratches and other surface irregularities of the neck. This packaging assembly however poses problems: polycarbonate is an expensive and relatively heavy material on the one hand and, the presence of an added gasket in the closure tends to give a spoiled odor and taste to the water contained in the bottle.
These problems are partly tackled by WO-A-2008/098362, which proposes a closure for closing a bottle without any added gasket. The seal is achieved by several outer sealing lips, which are applied on the outer face of the neck, including on the protruding bead with which this outer face is provided and around which an inner clip of the skirt of the closure is forcibly engaged, with flexible deformation of the closure until the clip is axially blocked against the bead of the neck.
For its part, WO-A-03/097475, on which is based the preamble of claim 1, discloses a closure interiorly provided with a sealing lip intended to cooperate with the inner face of the neck of a bottle. On paper, this solution seems appealing, but its practical application is thwarted: upon placement of the closure on the neck, an inner clip of the skirt of this closure interferes so much with an outer bead of the neck so as to in fine result in securing the contents of the bottle in the upside-down position, sufficiently strongly for withstanding, notably weight stresses, so that the closure undergoes overall deformation leading to bad positioning of the sealing lip relatively to the neck, or even to its squeezing between the free end surface of the neck and the remainder of the closure.
The bottle and the closure of DE-U-299 12 652 get round this problem by providing that the bead of the neck of the bottle is so far from the free end of this neck that, when this bead begins to interfere with the inner clip of the skirt of the closure, the free end of the neck is already facing radially a cylindrical running portion of a sealing lip with which the closure is interiorly provided: when the closure begins to deform under the effect of the interference between the aforementioned clip and bead, a large portion of this lip is therefore already accommodated inside the neck. This solution is of course not applicable to all the bottles.